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Comparison
Clock switch SLOW Clock switch FAST
Observation :
Represent waveform not constant but
periodic, PCM output totally based on input
but the shaped suppose to be the same with
PAM, while the clock have to constant period
and have big waveform as Channel 1
Observation :
Represent waveform constant and periodic,
PCM output totally based on input but the
shaped suppose to be the same with PAM,
while the clock have to constant period and
have small waveform as Channel 1
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8/14/2019 result lab 4 just part 2.docx
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Experiment 2: PCM Demultiplexing
1) In this experiment, as described on Figure 4.8, all the
required connections
have been done.
2) The input and output waves if Channel 1 Amplifier is have
been shown on the
oscilloscope is not crumpled.3) The necessary steps that the
upper and lower peaks are not distorted and the
voltage of limiting time have been verifying.
4) The same as experiment in process 2 and 3 have been done as
the remaining
channels.5) Next, as shown in Figure 4.10, all the necessary
connections have been
making and the clock was been sets to FAST.6) The oscilloscope
has been sets in 350Hz sinusoidal waveform of Channel 1
and the output was displayed on the screen.7) The waveform
displayed on the oscilloscope screen through process 6 have
been represent and attempt to listen to 350Hz of tone through
speaker.8) Input/ output of the remaining in channels 2 ~4 have
been perform in this
experiment
9) When the experiment was completed, switch off the power.
Channel Waveform Description
Chanel 1 Chanel 2
1 Not crumpled andamplitude 4Vpp
-Sine wave
Smooth and2Vpp
-Sine wave
2 -Not crumpled
-Smooth
-Small wave
-Sine wave
- 4Vpp
-Smooth
-Small wave
-Sine wave
-3Vpp
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8/14/2019 result lab 4 just part 2.docx
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3 -Not crumpled
-Smooth
-Small wave
-Sine wave
- 4Vpp
-Smooth
-Small wave
-Sine wave
-6Vpp
4 -Not crumpled-Smooth
-Small wave
-Sine wave
-4Vpp
Smooth andamplitude is
2Vpp.
-Sine wave
Observation
Based on waveform to represent the upper and lower peaks are not
distorted. The control
output is adjusted to make sure get not distortion and smooth
sine wave. Then make all the
connection and get the clock switch to FAST in order to increase
the frequency. The speaker
output for channel 1,speaker keep louder, channel 2 sound from
speaker became purr and
buzz but still louder, channel 3 have sound going shrill and as
though beep sounds. Finally
channel 4 sound are almost the same but getting more shrill and
when the same frequency as
in transmitting input (700Hz,1400Hz and 2800Hz) are being
received will be get result as
figure above.
